JP2005281796A - Surface treatment method and surface treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment method and surface treatment apparatus capable of uniformly performing a plasma treatment of respective surfaces of a substrate to be treated. <P>SOLUTION: The surface treatment method for working a member to be treated having a plurality of surfaces by the plasma discharge treatment includes a process (S 10) of arranging the member 150 to be treated between a plurality of counter electrodes within a chamber, processes (S 20 to S 40) of performing plasma discharge between the member to be treated and the plurality of the counter electrodes and measuring the electric constant of the chamber, a regulation process (S 50) of regulating the relative position relation between the surface to be treated of the member 150 to be treated and the plurality of counter electrodes opposed thereto, a process (S 60) of subjecting the surfaces to be treated to the surface treatment by the plasma between the member to be treated and the plurality of the counter electrodes. According to such configuration, the surface treatment is performed by regulating the respective electric constants between the respective surfaces to be treated of the member to be treated and the corresponding electrodes so as to make the constants approximately equal to each other and therefore the respective surfaces to be treated can be subjected to the uniform surface treatment by the one process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma processing method for forming a thin film on a surface of a substrate with a plasma gas and etching the surface of the substrate, and a plasma processing apparatus using the method.

For example, in the dry etching apparatus described in Japanese Patent Laid-Open No. 2001-259556, plasma etching is simultaneously performed on both surfaces of a substrate to be processed in order to shorten the processing time of a substrate that requires double-sided etching in single wafer processing. It has been proposed to improve the throughput.
JP 2001-259556 A

  However, if the substrate to be processed is large, the plasma etching amount tends to be non-uniform. Further, the plasma etching amount is different between the front surface and the back surface of the substrate to be processed, and it is difficult to uniformly etch the entire substrate to be processed. For example, pretreatment (etching) is performed in order to ensure adhesion between the thin film and the substrate in the step of coating the thin film on the metal separator (substrate) of the fuel cell component as the member to be treated. At that time, in order to shorten the processing time, it is desirable to perform simultaneous processing of a plurality of sheets and simultaneous processing of both surfaces (multiple surfaces) in one processing. In order to process a plurality of sheets at the same time, a surface treatment apparatus capable of processing a substrate having a large area (for example, 700 × 300 mm) is required, but such a scale is not provided. Uniform processing becomes difficult.

  Therefore, an object of this invention is to provide the surface treatment method and surface treatment apparatus which can perform the plasma processing of each surface of a to-be-processed substrate uniformly.

  In order to achieve the above object, a surface treatment method of the present invention is a surface treatment method for processing a member to be treated having a plurality of surfaces by plasma discharge treatment, wherein the member to be treated is placed between a plurality of counter electrodes arranged in a chamber. A process of arranging, a process of measuring the electric constant of the chamber by performing plasma discharge between the member to be processed and the plurality of counter electrodes, and facing the member to be processed based on the result of the measurement An adjustment process for adjusting a relative positional relationship with the plurality of counter electrodes, and a process for surface-treating the member to be processed with plasma between the member to be processed and the counter electrodes.

  According to such a configuration, the surface treatment is performed after adjusting the electrical constants between the counter electrodes corresponding to the surfaces to be processed of the processing target member to be the same, so that the surfaces to be processed are uniformly uniform at the same time. Surface treatment can be performed. Further, by performing the surface treatment after adjusting each surface to be processed to have an appropriate (individual) electrical constant, it is possible to perform individual surface treatment on each surface to be processed. Here, the relative positional relationship means a relative positional relationship in the three-dimensional space between the member to be processed and the counter electrode, and specifically includes adjusting at least one of the two to adjust the distance between them. The relative positional relationship is determined by the three-dimensional movement of at least one of the two, the neutrality of the positional relationship, the two-dimensional movement, or preferably the one-dimensional positional relationship. The relative positional relationship is adjusted by moving the side. The surface treatment includes etching, film formation, and the like.

  Preferably, in the adjustment process, the relative positional relationship is set so that an electrical constant between the member to be processed and the counter electrode facing the member to be processed is substantially equal for each surface to be processed. Thereby, it is possible to perform surface treatment with uniform surface conditions such as etching amount and film thickness on each surface to be treated.

  Further, the surface treatment method of the present invention is a surface treatment method for processing a member to be treated having a plurality of surfaces by plasma discharge treatment, a process of arranging the member to be treated between a plurality of counter electrodes arranged in the chamber, A process of measuring the electric constant of the chamber by performing plasma discharge between the member to be processed and the plurality of counter electrodes, and between the member to be processed and the plurality of counter electrodes based on the measurement result And adjusting the variable impedance disposed on the substrate, and simultaneously processing the plurality of surfaces to be processed by the plasma between the member to be processed and the plurality of counter electrodes.

  According to such a configuration, the surface treatment is performed after adjusting the electrical constant between the counter electrode corresponding to each surface to be treated of the member to be treated, so that uniform surface treatment can be simultaneously applied to each surface to be treated. It becomes possible.

  Preferably, in the adjusting process, the electrical constant is set for each processing surface by adjusting at least one of a relative positional relationship between the processing surface of the processing target member and the counter electrode and the variable impedance. To do.

  Thereby, the electric constant between the surface to be processed and the counter electrode can be adjusted by the relative positional relationship between the surface to be processed and the counter electrode and the variable impedance, so that the adjustable range becomes wider.

  Preferably, the edge of the member to be processed is arranged in the chamber with the edge held by a holder. Thereby, the movement / exchange (handling) of the member to be processed is facilitated, and the handling of the thin plate causing the bending is also facilitated.

  Preferably, the edge of the member to be processed is electrically connected to a high frequency power source via a holder. Thereby, it is possible to equalize the electric constant (distribution constant) by equalizing the potential on the member to be processed.

  Preferably, all the edges of the member to be processed are electrically connected to a high frequency power source via a holder. Thereby, it becomes possible to make the electric potential (distribution constant) uniform by equalizing the potential on the member to be processed.

  Preferably, there are a plurality of the members to be processed, and the edges of each member to be processed are held by one conductive holder and connected to a high-frequency power source through the holder, whereby the plurality of members to be processed Can be processed simultaneously. In addition, it is possible to easily handle the member to be processed and to equalize the potential on the member to be processed.

  Preferably, in the adjustment process, for each of the plurality of processing surfaces of the processing target member, an electrical constant is measured by the processing surface and a counter electrode corresponding to the processing surface, and the electrical constant of each processing surface is determined. A positional relationship between each surface to be processed and a plurality of counter electrodes corresponding to these surfaces to be substantially equal is obtained, and the plurality of counter electrodes corresponding to the member to be processed introduced into the chamber. Is set.

  Thereby, the positional relationship of the counter electrode to be set for each type of the member to be processed is determined in advance, and the processing time (adjustment) is performed by setting the position of each counter electrode according to the type of the member to be processed introduced. (Time) can be shortened.

  Preferably, the setting of the positional relationship between the plurality of counter electrodes is the setting of the shape of the plasma generation space in the chamber corresponding to the member to be processed. As a result, it is possible to perform surface treatment even on members to be processed having different shapes.

  Preferably, the member to be treated is a flat plate having front and back surfaces. The front and back surfaces are simultaneously surface-treated, or one surface is selectively surface-treated.

  Preferably, the flat plate is a fuel cell separator.

  Preferably, in the adjustment process, the surface treatment state of each surface is made different by adjusting the relative positional relationship between the surface to be processed of the member to be processed and the counter electrode corresponding to the surface.

  Preferably, the adjustment process inactivates the surface treatment on the surface to be processed by setting the distance between one surface to be processed and the counter electrode facing the surface to be a predetermined value or less. It is. Since the surface treatment of the surface can be prohibited by setting the inter-electrode distance (gap) of one surface to a predetermined value or less, it is possible to set a surface to be subjected to surface treatment and a surface not to be performed in one process. . Therefore, it is possible to perform one-side processing to multi-side processing in one process (in the same chamber).

  Moreover, the surface treatment apparatus of the present invention is a surface treatment apparatus for processing a member to be treated having a plurality of surfaces by plasma discharge treatment, and a plurality of the treatment members disposed to face the plurality of treatment surfaces of the member to be treated. The relative position relationship between the counter electrode, the chamber to be processed and the plurality of counter electrodes in a process gas atmosphere, and the relative positional relationship between the member to be processed and the counter electrodes is adjusted for each surface to be processed. And a high-frequency power source that supplies high-frequency power between the member to be processed and the plurality of counter electrodes to generate plasma between the plurality of surfaces to be processed and the plurality of counter electrodes.

  According to such a configuration, the surface treatment is performed after adjusting the electric constants between the counter electrodes corresponding to each surface to be processed of the member to be processed, so that uniform surface treatment can be performed simultaneously on each surface to be processed. Can be applied. Further, when adjustment is made so that an appropriate (individual) electrical constant is obtained for each surface to be processed, individual surface treatment can be performed on each surface to be processed in one process.

  Preferably, the adjusting means sets the relative positional relationship such that an electric constant between the member to be processed and the counter electrode is substantially equal for each surface to be processed.

  Thereby, the electric constant between the surface to be processed and the counter electrode can be adjusted by the relative positional relationship between the surface to be processed and the counter electrode and the variable impedance, so that the adjustable range becomes wider.

  Further, the surface treatment apparatus of the present invention is a surface treatment apparatus for processing a member to be treated having a plurality of surfaces by plasma discharge treatment, and a plurality of members disposed respectively facing the plurality of treatment surfaces of the member to be treated. A counter electrode; a chamber for maintaining the member to be processed and the plurality of counter electrodes in a process gas atmosphere; and a variable impedance electrically connected between the member to be processed and each of the plurality of counter electrodes. Adjusting means for adjusting the electric constant between the member to be processed and the counter electrode for each surface to be processed; and supplying the high-frequency power between the member to be processed and the plurality of counter electrodes to provide the plurality of surfaces to be processed. And a high-frequency power source for generating plasma between the plurality of counter electrodes.

  According to such a configuration, the surface treatment is performed after adjusting the electrical constant between the counter electrode corresponding to each surface to be treated of the member to be treated, so that uniform surface treatment can be simultaneously applied to each surface to be treated. It becomes possible.

  Preferably, the adjusting means adjusts at least one of a relative positional relationship between the surface to be processed of the member to be processed and the counter electrode and the variable impedance, and sets the electric constant for each surface to be processed. To do.

  Thereby, the electric constant between the surface to be processed and the counter electrode can be adjusted by the relative positional relationship between the surface to be processed and the counter electrode and the variable impedance, so that the adjustable range becomes wider.

  Preferably, the adjusting means measures in advance the electric constants of the surface to be processed and the counter electrode corresponding to the surface to be processed, and the electric constant of each surface to be processed is determined. A positional relationship between each surface to be processed and a plurality of counter electrodes corresponding to these surfaces to be substantially equal is obtained, and the plurality of counter electrodes corresponding to the member to be processed introduced into the chamber. Is set.

  The positional relationship between the counter electrodes to be set for each type of the member to be processed is determined in advance, and the processing time (adjustment time) is set by setting the position of each counter electrode according to the type of the member to be processed introduced. It becomes possible to shorten.

  Preferably, the setting of the positional relationship between the plurality of counter electrodes is the setting of the shape of the plasma generation space in the chamber corresponding to the member to be processed.

  Preferably, the adjusting means varies the surface treatment state of each surface by adjusting the relative positional relationship between the surface to be processed of the member to be processed and the counter electrode corresponding to the surface.

  Preferably, the adjusting means prevents surface treatment on the surface to be processed by setting a relative positional relationship between one surface to be processed and the counter electrode facing the surface to be a predetermined value or less. It is to activate.

  Since the surface treatment of the surface can be prohibited by setting the distance between the opposing electrodes of one surface to a predetermined value or less, it is possible to set a surface to be subjected to the surface treatment in one process and a surface not to be performed. Accordingly, it is possible to perform from one-side processing to multi-side processing in one process.

  Preferably, the member to be processed is arranged in the chamber with its edge held by a holder.

  Preferably, the edge of the member to be processed is held by a conductive holder, and is electrically connected to a high-frequency power source through the holder.

  Preferably, the member to be treated is a flat plate having front and back surfaces.

  Preferably, the flat plate is a fuel cell separator.

  Preferably, the plasma discharge treatment is etching or film formation.

  In addition, the plasma processing apparatus of the present invention includes a member to be processed having a surface to be treated for plasma processing, and a conductive holder that holds an outer periphery of the member to be processed in a state where the surface to be processed is exposed. A counter electrode disposed to face the surface to be processed, a variable impedance for adjusting an electrical constant between the holder and the counter electrode, a high frequency power source for supplying high frequency power between the counter electrode and the holder, Is provided.

  By configuring the variable impedance between the holder and the counter electrode, the entire member to be processed is covered with the counter electrode, and the portions where the electrical constants of the outer periphery of the processing member and the end of the counter electrode are disturbed are adjusted by the variable impedance. The Thereby, the distribution of the electric constant between the member to be processed and the counter electrode is made uniform as a whole, and the surface treatment is made uniform.

  In addition, the plasma processing apparatus of the present invention includes a member to be processed having a surface to be treated for plasma processing, and a conductive holder that holds an outer periphery of the member to be processed in a state where the surface to be processed is exposed. , A counter electrode disposed opposite to the surface to be processed, a variable impedance for adjusting an electric constant between the holder and the counter electrode, and high-frequency power supplied through a feeder line between the counter electrode and the holder A high-frequency power supply that detects the supply state of the high-frequency power in the power supply line, and a control unit that adjusts the variable impedance based on the detection result.

  By adopting such a configuration, the matching condition in the plasma processing apparatus is further determined, and the electric constant is adjusted. The process is automated and good. The electrical constant may be adjusted by adjusting at least one of the relative positional relationship between the member to be processed and the counter electrode and the variable impedance.

  For example, the holder includes two frames that sandwich the processing target member and a clamp that holds the two frames. A protrusion serving as a power supply end from the power supply line is provided outside the intermediate portion of the frame.

  The holder is disposed such that a plurality of surfaces to be processed of the member to be processed are exposed, and a plurality of counter electrodes face each of the surfaces to be processed. In order to make it possible to adjust the relative position between the member to be processed and the counter electrode, for example, the counter electrode is configured to have a variable height. A plurality of variable impedances can be provided corresponding to a plurality of surfaces to be processed and a plurality of counter electrodes. The electrical constant is adjusted by the relative positional relationship between the member to be processed and the electrode and the variable impedance. The variable impedance can be arranged inside and outside the chamber.

  Further, the surface treatment apparatus of the present invention provides a first and second electrodes that are spaced apart so that the concave openings face each other, and a treatment target between the first and second electrodes. The substrate disposed so that the surface faces the opening and the region of the surface to be processed is within the region of the opening, the first and second electrodes, and the substrate are maintained in a reduced-pressure atmosphere. A chamber, gas supply means for supplying a process gas into the chamber, and a high-frequency power source for supplying high-frequency power between the substrate and the first and second electrodes to turn the process gas into plasma. Prepare.

  With this configuration, the substrate and the concave electrodes (for example, box-shaped electrodes) covering both sides of the substrate prevent plasma diffusion and collect plasma in the vicinity of the substrate, thereby enabling uniform surface treatment on both sides of the substrate. .

  Preferably, the concave openings of the first and second electrodes are formed in the same shape. As a result, the electrical constants of the plasma spaces on the front and back of the substrate are substantially equal, and uniform surface treatment is performed on both sides of the substrate.

  Preferably, each of the first and second electrodes includes a movable electrode that is disposed at the bottom of the concave opening and moves forward and backward in the direction of the substrate. This makes it possible to adjust the electrical constant by changing the shape of the plasma space (or the relative positional relationship between the substrate and the counter electrode).

  Preferably, each electrical constant between the first and second electrodes and the substrate is set equal. Thereby, it can be expected that the same plasma state is generated on the front and back of the substrate and the same surface treatment is performed.

  Preferably, the first and second electrodes have a box shape. In general, a substrate to be processed is a rectangular plate-like member, and a box shape is good.

  According to the present invention, it is possible to perform a uniform surface treatment on each processing surface of a processing target member having a plurality of processing surfaces. In addition, it is possible to perform surface treatment with different degrees on each surface to be processed for each surface to be processed.

  First, elemental techniques in the surface treatment method of the present invention and the surface treatment apparatus using this method will be described.

(Wide substrate area processing)
In the embodiment of the present invention, the plasma discharge space in the vicinity of the member to be processed is defined by the space constraining parts so that an appropriate discharge space shape can be obtained. For example, the same plasma discharge space is formed on both sides of the substrate to be processed. Further, in order to process both surfaces (a plurality of surfaces) of the member to be processed at the same time, the plasma is confined in the container so that the member to be processed is sandwiched between two space-constraining parts constituting the container partially opened. Prevent diffusion. The space constraining parts include, for example, a box reflector, an impedance shield, a metal block, an insulating block, a tray, and the like which will be described later.

  The box reflector is a box-shaped member having an opening facing the member to be processed, and a partition is provided in the opening to divide the region corresponding to the member to be processed from other regions, and the region corresponding to the member to be processed. The member to be processed is covered with. Two surfaces of the member to be processed are covered with two box reflectors. This prevents plasma diffusion on both sides of the member to be processed and achieves uniform etching.

(Suspension board adjustment)
By changing the height of the bottom plate at the bottom of the opening of the box reflector, the shape of the space (plasma space) formed by the member to be processed and the box reflector can be adjusted. This corresponds to the fact that the electric constant of the chamber can be adjusted electrically. The box reflector and the bottom plate at the bottom of the opening serve as one electrode (counter electrode) for generating plasma, and the member to be treated serves as the other electrode (direct discharge method). A bias voltage (direct current (DC) voltage supply or self-bias voltage) is applied to the member to be processed, and ions or radicals generated in the plasma collide with the member to be processed, and etching is performed.

(Impedance shield)
The outer periphery of the substrate to be processed is surrounded by an impedance shield or a metal block, and the disturbance of the electric field generated between the outer periphery of the substrate to be processed and the outer periphery of the counter electrode and the outward diffusion of plasma are prevented. The impedance shield is, for example, a metal plate-like body arranged so as to be opposed to each other at a constant interval, and can be configured as a so-called variable capacitor (variable capacitor) to provide a variable impedance (provided in the chamber). Can function. The impedance shield and the metal block are connected to a predetermined potential (for example, ground potential) to stabilize the electric field (potential) in the chamber.

(holder)
The member to be processed is, for example, a thin metal substrate, the outer periphery (edge) of which is held by a frame-shaped holder so that the front and back surfaces of the substrate are exposed, and held between the opposing electrodes of the two box reflectors. Is done. Thereby, simultaneous plasma processing on both sides of the substrate becomes possible. The holder can hold a plurality of substrates, thereby enabling the processing of a plurality of substrates simultaneously. A feeding point is set on the frame of the holder. By supplying a high-frequency power from the holder to the outer periphery of the substrate instead of on the substrate and supplying high-frequency power from the holder to the outer periphery of the substrate, the substrate that is easily bent is uniformly held, and a uniform potential is applied to the entire substrate as much as possible. . In addition, feeding of power to the substrate through the holder avoids the generation of traces of feeding points on the surface of the substrate. For example, to prevent the substrate held by the holder from being bent or warped due to thermal expansion, the holder is made of the same kind of (conductive) material as the substrate. The holder is attached to the central portion of the hollow tray for conveyance via an insulating material. The holder and the tray are insulated from each other, and discharge from the tray is prevented. Further, the influence of the tray shape is eliminated. The member to be processed and the holder move between the chambers of the plurality of process apparatuses while being placed on the transfer tray.

(Polyhedron processing)
The member to be processed is typically a flat plate substrate, and by applying the present invention, the same processing (for example, etching processing or sputtering processing) can be uniformly performed on both surfaces simultaneously. This can be applied to a polyhedron such as a polygonal cylinder or a cylinder. By adopting a structure in which a movable counter electrode is provided for each surface to be processed of the polyhedron, it is possible to adjust the electric constant for each surface to be processed and to achieve uniform plasma surface treatment.

  In addition, by individually setting the movable counter electrode in a state (condition) where plasma is generated and a state where plasma is not generated, it is possible to selectively process the corresponding surface of the member to be processed having a plurality of surfaces. is there. For example, an apparatus that performs plasma processing on both sides of a substrate can be made to function as an apparatus that performs plasma processing on one side of a substrate with the same configuration.

(Alignment)
In the plasma processing apparatus of the present invention, high frequency energy for generating plasma between the electrodes is supplied from a high frequency power source via a transmission line. The transmission line is constituted by a waveguide or a high frequency cable. A measurement unit is provided in the middle of the transmission line to measure traveling wave power, reflected wave power, phase difference between supply voltage and supply current, standing wave, and the like. Based on the result, the control unit adjusts the above-described relative positional relationship between the counter electrode and the substrate, variable impedance, and the like. An external impedance circuit (matching circuit) and an internal impedance circuit are prepared for the variable impedance. For example, the external impedance circuit is provided in a matching box adjacent to the chamber. By matching the power supply system and the chamber by setting an appropriate electric constant, a stable plasma is formed with a minimum power supply loss. The internal impedance circuit can be provided in an impedance shield part in the chamber. For example, the variable shield structure of the impedance shield part is used. By further adding an internal impedance circuit, matching can be achieved in a wider range. Ions and radicals in the plasma collide with the substrate by applying a DC bias voltage or a so-called self-bias voltage to the substrate to be processed, and uniform surface treatment is performed.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory view (cross-sectional view) schematically showing a state (see FIG. 10 described later) in which a chamber portion of an etching apparatus which is a plasma processing apparatus of the present invention is horizontally cut and viewed from above. .

  In the figure, a first base frame 301 and a second base frame 351 are arranged in parallel at a predetermined interval so as to face each other to form a chamber space. A tray 100 on which a substrate (substrate to be processed) 150 to be etched is placed so as to be parallel to the base frames 301 and 351 is disposed in the approximate center of the chamber space.

  A first box reflector 302 is disposed on the surface side (inside) of the base frame 301 that faces the base frame 351 (or the tray 100). The box reflector 302 is made of metal (conductive) and has a box shape, and its bottom is directed to the base frame 301 and its opening is directed to the tray 100. The bottom plate of the box reflector 302 is a first counter electrode 303. The counter electrode 303 is configured to be able to advance and retreat in the tray 100 direction by an actuator 304 that generates a driving force for moving the counter electrode 303 and a plurality of guides 305 that guide the movement. The outer shape of the counter electrode 303 is larger than the substrate 150 and smaller than the outer shape of the tray 100.

  A first impedance shield 306 is disposed on the outer edge of the counter electrode 303 so as to face the tray 100. As will be described later, the impedance shield 306 surrounds the outer periphery of the counter electrode 303, and its main surface faces the tray 100. The impedance shield 306 includes a parallel plate electrode group in which a plurality of metal plates (conductors) are arranged in parallel (see FIG. 16). Thereby, the electric field in the outer edge region of the space defined by the counter electrode 303 and the substrate 150 is stabilized. Further, diffusion of plasma out of the substrate 150 is suppressed.

  Similarly, a second box reflector 352 is disposed on the side (inner side) of the base frame 351 facing the base frame 301 (or the tray 100). The box reflector 352 is made of metal (conductive) and has a box shape, and its bottom is directed to the base frame 351 side and its opening is directed to the tray 100 side. The bottom plate of the box reflector 352 is a second counter electrode 353. The counter electrode 353 is configured to be able to advance and retreat in the tray 100 direction by an actuator 354 that generates a driving force for moving the counter electrode 353 and a plurality of guides 355 that guide the movement. The outer shape of the counter electrode 353 is larger than the substrate 150 and smaller than the outer shape of the tray 100.

  A second impedance shield 356 is disposed on the outer edge of the counter electrode 353 so as to face the tray 100. As will be described later, the impedance shield 356 surrounds the outer periphery of the counter electrode 353, and its main surface faces the tray 100. The impedance shield 356 includes a parallel plate electrode group in which a plurality of metal plates (conductors) are arranged in parallel (see FIG. 17). Accordingly, the electric field in the outer edge region of the space defined by the counter electrode 353 and the substrate 150 is stabilized. In addition, plasma diffusion is suppressed.

  FIG. 2 schematically shows a surface of the tray 100 and the substrate 150 facing the counter electrode 303 (or 353). A specific configuration example will be described later with reference to FIG.

  As shown in the figure, a plurality of substrates 150 to be etched (surface treatment) are held by a holder 120. As will be described later, the holder 120 can have a structure in which the substrate 150 is sandwiched between two frames, for example. The two frames can be fixed with clips. In addition, a plurality of substrates 150 can be held between the two frames while being separated from each other. A holder 120 that holds a plurality of substrates is made of a conductive member (metal) and is attached to the tray 100 via an insulating member 110. Two feeding terminals (feeding points) 121 are provided on the left and right axes of the holder 120 so as to protrude outward. By energizing the substrate 150 through the power supply terminal 121, it is possible to avoid leaving a trace of power supply on the substrate 150. The tray 100 is held in the chamber so as to be movable at both ends in the longitudinal direction (both ends in the left-right direction in the figure).

  In such a configuration, a process gas is introduced into the chamber, and high-frequency power is applied between the substrate 150 and the first counter electrode 303 and the second counter electrode 353, thereby generating plasma on both sides of the substrate 150. Occurs. Further, by applying a direct current bias to the substrate 150, radicals generated by the plasma collide with the substrate 150, and (anisotropic) etching of a plurality of surfaces (front and back surfaces) of the substrate is performed.

  FIG. 3 shows a state where the above-described counter electrode is moved. In the figure, parts corresponding to those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

  The counter electrodes 303 and 353 can be moved independently by the respective actuators 304 and 354. Since each counter electrode can be set at an arbitrary height position from the bottom of the box reflector, the relative positional relationship (distance) between the substrate 150 and the counter electrode 303 and the relative positional relationship between the substrate 150 and the counter electrode 353 are arbitrary. The position (distance) can be set. This means that the electrical constant of the electrical circuit (discharge space) in the plasma discharge apparatus can be adjusted from an electrical viewpoint.

  It has been experimentally found that when the counter electrode 303 or 353 is brought closer to the substrate 150, there is a separation distance (plasma extinction distance) at which the plasma discharge disappears in the space. Therefore, for example, when the counter electrode 303 is set to be equal to or less than the plasma extinction distance and the counter electrode 353 is set to be equal to or greater than the plasma extinction distance, the etching process on the first surface side of the substrate 150 is not performed, and only the second surface side is performed. An etching process (single-sided etching process) can be performed. Therefore, for example, in the case where the counter electrode is arranged corresponding to each surface of the polygonal column substrate (member to be processed), the simultaneous etching process of each surface is performed by appropriately setting the distance between each counter electrode and the substrate. In addition, the selected surface can be etched.

  FIG. 4 is a block diagram illustrating a control system of the etching processing apparatus 30 described above.

  As shown in the figure, the high frequency power supply 381 is connected between a substrate (substrate electrode) 150 in the chamber and the counter electrodes 303 and 353 via a feeder line 384 made of a high frequency cable and an external variable impedance circuit (matching box) 385. Supply high frequency power. As described above, the counter electrodes 303 and 353, the box reflectors 302 and 352, and the impedance shields 306 and 356 forming the closed space (chamber) are connected to the chamber case 386 having a predetermined potential (for example, ground potential). The positions of the counter electrodes 303 and 353 are adjusted by the space adjustment unit 387. The space adjustment unit 387 corresponds to the actuators 304 and 354 and the guides 305 and 355 that set the positions of the individual counter electrodes.

  A CM type wattmeter 382 is connected in the middle of the feeder line 384, and the traveling wave power and reflected wave power on the feeder line are measured. Further, an impedance measuring device 383 for measuring a phase difference θ (power factor) between the voltage and current on the line and an impedance Z is connected to the feeder line 384. These measurement results are sent to the control unit 390.

  FIG. 5 shows a configuration example of the external variable impedance circuit 385. As shown in the figure, the circuit 385 includes an inductor L and a variable capacitor (variable capacitor) Cc connected between the center conductor of the high-frequency cable 384 and the substrate electrode 150, and a variable capacitor connected between the center conductor and the ground. It is comprised by Ci. These variable capacitors are adjusted to eliminate the phase difference θ and to achieve impedance matching between the high frequency cable and the chamber. The configuration of the external variable impedance circuit 385 is merely an example, and is not limited to that shown in FIG. For example, the inductor L can be configured such that the inductance value can be changed by a variable reactor.

  Process gas is introduced into the chamber by an intake pump 388. Further, the gas in the chamber is discharged to the outside by an exhaust pump 389.

  The control unit 390 is sold and configured by an available control computer system. This computer system includes a CPU, RAM, ROM, HDD, interface, and the like (not shown), and the function of the control unit is realized by the CPU executing a control program.

  The control unit 390 executes an etching process by controlling a tray transfer device (not shown), a space adjustment unit 387, pumps 388 and 389, an external variable impedance circuit 385, a high frequency power supply 381, and the like.

  FIG. 6 is a flowchart for explaining the control operation of the control unit 390 in the etching apparatus 30.

  First, the control unit 390 stores an optimum gap between the substrate and the counter electrode determined for each product number (type) of the substrate (work) 150 obtained in advance by experiments or the like in a memory as a table, and is loaded. The interval between the counter electrodes 303 and 353 is set to the initial state (coarse adjustment position) corresponding to the product number of the substrate 150. For example, the control unit 390 reads a code (for example, a bar code, a block code, a tag, etc.) displayed on the tray 100 or the substrate 150 with a camera (not shown) provided during the process, and determines the code by pattern recognition. The above table can be referred to based on the determined code. Also, the product number of the substrate 150 to be processed can be obtained as process information from a process management computer or the like that manages the process. The controller 390 opens the gate valve (see FIG. 9) of the chamber of the etching apparatus 30 and carries the tray 100 on which the substrate 150 is placed via the holder 120 into the chamber of the etching processing apparatus. When the tray 100 is held at a predetermined position in the chamber, the gate valve is closed to make the chamber a closed space (S10).

  In addition, after carrying in tray 100, it is good also as controlling space adjustment part 387 and setting each separation distance (gap) between substrate 150 and counter electrodes 303 and 353.

  The controller 390 operates the exhaust pump 389 to depressurize the sealed chamber. When the pressure in the chamber is reduced to a predetermined pressure, the control unit 390 opens a valve of a gas supply path (not shown), operates the intake pump 387, and introduces process gas into the chamber while adjusting the flow rate with a mass flow controller (not shown). . Further, the control unit 390 operates the exhaust pump 389 to keep the process gas concentration in the chamber in a predetermined state so that the gas used for etching is exhausted. The type of process gas is selected according to the material of the substrate to be etched. For example, argon gas can be used (S20).

  The control unit 390 causes the high-frequency power supply 381 to supply high-frequency power determined in advance corresponding to the substrate to generate plasma in the chamber. The high frequency power supply 381 also has a function of applying a DC bias voltage to the substrate 150. Plasma ions and radicals are pulled by the DC bias voltage and collide with the substrate 150 to perform anisotropic etching. This bias voltage is one of the control parameters for anisotropic etching. Note that anisotropic etching may be performed by using the conductive substrate 150 side as a cathode and generating a self-bias voltage (Vdc) by a so-called ion sheath phenomenon. Further, instead of applying a DC bias, etching may be performed by applying a relatively low high-frequency power of about 400 kHz that can be followed by ions between the electrodes (S30).

  The control unit 390 observes the output of the CM type wattmeter 382 (traveling wave power, reflected wave power, supplied power as a difference between them). For example, the level of the reflected wave power (reflectance) can be used as an index for determining whether or not matching adjustment is necessary. Further, the control unit 390 observes the output of the impedance measuring device 383 to know the power factor and the chamber impedance (S40).

  When the control unit 390 determines that the matching adjustment is necessary based on the reflected power level, the shift between the characteristic impedance of the feeder line and the impedance of the chamber, etc., the control unit 390 adjusts the electrical constant of the external variable impedance circuit to match the impedance. For example, the phase difference is reduced by adjusting the variable capacitor Ci. The impedance difference is adjusted by adjusting the variable capacitor Cc.

  In order to achieve more accurate alignment, the relative positional relationship (distance adjustment) between the substrate 150 and the counter electrodes 303 and 353 that affect the electrical constant of the chamber can be added to the adjustment items. It is preferable to set the closed spaces defined by the counter electrodes on both sides of the substrate 150 to be symmetrical in order to set the etching amounts on the front and back of the substrate equally (S50).

  When the alignment is achieved and the plasma is stabilized, etching is performed until a predetermined amount of the substrate surface is removed (S60). The controller 390 terminates the etching process when a predetermined amount of removal is performed or when a time corresponding to the predetermined removal amount elapses.

  Note that the control unit 390 performs supply high-frequency power in the impedance measurement stage with test power (relatively low power) in consideration of measuring instrument performance and the like, and performs operation power (relatively high power) in the etching execution stage. It's also good.

  Further, the control unit 390 stores the impedance setting values of the respective parts determined in advance for each product number (type) of the substrate, and corresponds to the product number of the substrate to be loaded without performing the impedance measurement (S40) described above. Then, the above-described electrical constants such as the inter-electrode gap (electrical constant), the external variable impedance circuit 385, the internal variable impedance circuit 385a, etc. may be set to appropriate values. Thereby, it is possible to shorten the processing time (improve production efficiency) for the same lot.

  FIG. 7 is a block diagram for explaining another control system of the etching processing apparatus 30. In the figure, parts corresponding to those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

  In this embodiment, a variable impedance circuit 385a is provided in the chamber case 386. Other configurations are the same as those in FIG.

  A variable impedance circuit 385a is provided inside the chamber, and this is controlled by the control unit 390 so that the electric constant of the chamber can be adjusted in a wider range. The variable impedance circuit 385a is constituted by, for example, a variable capacitor (variable capacitor) as shown in FIG. This variable capacitor is realized by using the impedance shields 306 and 356 described above as a variable capacitor configuration. Each variable condenser is adjusted by the control unit 390.

  FIG. 9 schematically shows a thin film forming apparatus including the etching apparatus 30 which is the surface processing apparatus described above as a pretreatment apparatus as viewed from above. The thin film forming apparatus performs surface treatment (pretreatment) on both surfaces of a substrate by etching, and then forms a film on the substrate surface by sputtering.

  In the figure, the thin film forming apparatus 1 is schematically shown as a tray carrying-in device 10, a loading device 20, an etching device 30, a first sputtering device 40, a second sputtering device 50, an unloading device 60, a tray carrying-out device 70, and a tray. A return device 80 is provided. Gate valves G <b> 1 to G <b> 6 are provided between the devices to enable movement of the transfer tray 100 between the devices and individual atmosphere setting of the chambers in the devices.

  First, a plurality of substrates 150 to be processed are held by the holder 120 and fixed (placed) on the transfer tray 100 by an assembler (or an assembly apparatus). The tray 100 is placed at the set position of the tray carry-in device 10. The tray carry-in device 10 conveys the tray 100 toward the load device 20, passes through the gate valve G <b> 1, and carries it into the load unit 20.

  When the tray 100 is loaded, the load device 20 depressurizes the chamber and preheats the substrate 150 to a predetermined temperature. Thereafter, the tray 100 passes through the gate valve G2 and is conveyed to the etching apparatus 30.

  As described above, the etching apparatus 30 is a surface processing apparatus that performs plasma processing together with the subsequent sputtering apparatuses 50 and 60. The etching apparatus 30 introduces a process gas (etching gas) under a reduced-pressure atmosphere, supplies high-frequency power between the substrate 150 and the electrode, converts the process gas into plasma, activates it, and etches the surface of the substrate 150. In the example of the thin film forming apparatus 1, the front and back surfaces of the substrate 150 are simultaneously etched. Further, it is possible to perform etching on only one side. After the etching is completed, the tray 100 on which the substrate 150 is placed passes through the gate valve G3 of the next stage and is conveyed to the first sputtering unit 40.

  The first sputtering apparatus 40 forms a first film made of metal or the like on the preprocessed (etched) substrate 150 by sputtering in a reduced pressure atmosphere. Further, the tray 100 passes through the gate valve G4 of the next stage and is conveyed to the second sputtering apparatus 50. Furthermore, the second sputtering apparatus 40 deposits a second film such as a metal on the substrate 150 on which the first film is formed by a sputtering method in a reduced pressure atmosphere. The first sputtering apparatus 40 may form a film on one surface of the substrate 150 and the second sputtering unit 50 may form a film on the other surface of the substrate.

  In this way, the tray 100 on which the substrate 150 having the thin film formed thereon is loaded and carried into the unloading device 60 through the gate valve G5 of the next stage.

  The unload device 60 returns the substrate 150 to room temperature. Moreover, it returns to a normal pressure atmosphere from a series of decompression atmosphere environment. The substrate 150 is transferred to the tray carry-out device 70 through the gate valve G6. The tray carry-out device 70 conveys the tray 100 to the tray return device 80. The tray return device 80 returns the tray 100 on which the processed substrate is placed to the original setting position of the tray carry-in device 10. The processed substrate is removed from the tray 100 by an assembler or the like. A holder holding a new substrate to be processed 150 is placed on the tray 100 and reused.

  A specific configuration example of the above-described etching apparatus 30 will be described. FIG. 10 is a perspective view showing a state in which the upper half of the chamber portion of the etching apparatus 30 is cut and the inside of the chamber is viewed from the upper right of the apparatus. FIG. 11 is a right side view of the etching apparatus shown in FIG. 10 and 11, the same reference numerals are given to the portions corresponding to those in FIGS.

  As shown in FIGS. 10 and 11, the chamber of the etching apparatus 30 is configured between base frames 301 and 351 arranged to face each other at a predetermined distance. A box reflector 302 is provided on the side of the base frame 301 that faces the base frame 351. The bottom of the box reflector 302 is a movable counter electrode 303 that moves along partition plates 302a to 302d surrounding the periphery from four sides. Similarly, a box reflector 352 is provided on the side of the base frame 351 that faces the base frame 301. The bottom of the box reflector 352 is a movable counter electrode 353 that moves along partition plates 352a to 352d that surround the box reflector 352 (see FIG. 12). The movable counter electrodes 303 and 353 are movable by guides 305 and 355 and actuators 304 and 354, respectively.

  12 and 13 are perspective views showing a specific configuration example of the box reflector 352 described above. 12 shows a state where the counter electrode 353 which is the bottom plate of the box reflector 352 is lowered to the bottom side, and FIG. 13 shows a state where the counter electrode 353 is raised from the bottom by an actuator 354 not shown. Although not shown, the counter electrode 303 is also movable in the box reflector 302 as well.

  As shown in both drawings, the box reflector 352 is formed of a metal (conductor) box-like body and includes partition plates 352a to 352d surrounding the counter electrode 353. A plasma generation space is defined by the partition plates 352a to 352d, the counter electrode 353, the substrate 150, the holder 120, and the like. The recessed portions on the left side surface and the right side surface of the box reflector 352 shown in the figure serve as a space for supplying power to the power supply terminal 121 of the holder 120. The box reflector 302 is configured in the same manner. However, since power is supplied to the chamber from the side of the box reflector 352, the left and right side recesses as in the box reflector 352 are not provided.

  As shown in FIG. 10, there is an impedance shield 306 between the outer region (non-plasma formation region) of the partition plates 302 a to 302 d (only 302 a and 302 b are shown in the figure) of the box reflector 302 and the holder 120 and the tray 100. Is provided. Similarly, an impedance shield 356 is provided between the box reflector 352, the holder 120, and the tray 100. As described above, the impedance shields 306 and 356 stabilize the electric field (potential) in the outer peripheral region of the chamber.

  14 and 15 show examples of the shape of the unit plate 306a constituting the impedance shield 306. FIG. In the example shown in FIG. 14, the unit plate 306 a is constituted by a plurality of plate bodies in consideration of thermal deformation of the impedance shield 306. By dividing and providing a gap between the plates, it is difficult for the plates to be bent due to thermal expansion.

  FIG. 15 shows an example (single-piece type) of unit impedance shield constituted by a single “B” -shaped plate having an opening at the center. This is convenient when thermal expansion is not particularly problematic or when a member that is not easily bent due to thermal expansion is used.

  FIG. 16 is a perspective view for explaining a state in which a split type impedance shield 306 in which a plurality of unit plates 306a are stacked in parallel through an air gap is attached to the box reflector 302. FIG.

  FIG. 17 is a perspective view for explaining a state where a split-type impedance shield 356 in which a plurality of unit plates 356a are stacked in parallel through an air gap is attached to the box reflector 352. FIG. In order to secure a power supply space to the power supply terminal 121 of the holder 120, recesses are formed on the left and right sides of the illustrated impedance shield 356 corresponding to the left and right recess shapes of the box reflector 352, respectively.

  As shown in FIGS. 10 and 11, a matching box in which a variable impedance circuit is formed outside the base frame 351 so as to be adjacent to the chamber so as to match the electrical constant (impedance) of the chamber and the characteristic impedance of the feeder line 384. 385 is provided. In the matching box 385, the inductor L, capacitors Cc and Ci shown in FIG. The high frequency power supplied to the matching box (variable impedance circuit) 385 is supplied to the power supply terminal 121 of the holder 120 through the terminal connection portions 385a and 385b. The terminal connecting portions 385a and 385b are configured such that the conductive shaft advances and retracts (or expands and contracts) in the axial direction by a screw mechanism so that the holder 120 and the tray 100 can be moved in and out of the chamber. When the conductive shaft advances (extends), the tip of the conductive shaft comes into contact with the power supply terminal 121 of the holder 120 as a connection terminal to be electrically connected, and high-frequency power is supplied to the substrate 150. When the conductive shaft is retracted, the tip of the conductive shaft is separated from the power supply terminal 121 of the holder 120, and the electrical connection is interrupted. The tray 100 can be transported (moved) by separating the connection terminals.

  The above-described impedance shields 306 and 356 are configured by a parallel plate electrode group having a gap as an insulator. This can be configured as a so-called variable capacitor (variable capacitor). As a result, an internal variable impedance circuit can be formed inside the chamber, and the adjustment range of the electric constant in the chamber can be made wider, and the matching range with the power feeding system can be expanded. In addition, it is possible to stabilize the plasma by changing the electric constant of the internal variable impedance in response to the change of the plasma state (change of the electric constant). Furthermore, it is possible to adjust the electric constant in a wider range by adjusting the internal variable impedance at the time of adjusting each gap between the counter electrodes 303 and 353 and the substrate 150 (see FIG. 8).

  FIG. 18 is a perspective view illustrating a configuration example of the holder 120. As shown in the figure, the holder 120 is composed of two hollow frames 120 a and 120 b and clamps (or clips) 131 and 132. A plurality of substrates 150 to be processed arranged on the same plane are fixed by being sandwiched between two frames 120a and 120b. In a state where a plurality of substrates 150 are sandwiched, the two frames 120a and 120b are sandwiched and fixed by clamps 131 and 132 having U-shaped cross sections on the left and right sides thereof. Two power supply ends 121 extending outward from the frame are provided on the symmetry axes of the frames 120a and 120b. As described above, the high-frequency power and the DC bias are applied to the power supply end 121. The frames 120a and 120b are made of the same material as the substrate 150 to be processed, for example, a metal plate. Thereby, it becomes the same expansion coefficient and a bending etc. are prevented. Further, the outer periphery of the substrate 150 is held by the conductive frames 120a and 120b, so that the surface of the substrate 150 has the same potential.

  The holder holding the plurality of substrates 150 in this manner is placed (fixed) on the tray 100 via the insulator 110 as shown in FIG.

  In the above-described embodiment, the box reflectors 302 and 352 and the impedance shields 306 and 356 are used as members for defining the shape of the chamber space, but the present invention is not limited to this.

  For example, as shown in FIG. 19, a metal block can be used in place of the box reflector 302 and the impedance shield 306. The metal block is composed of a combination of metal members.

  In addition, as shown in FIG. 20, a metal block in which a recess is formed in the power feeding space can be used instead of the box reflector 352 and the impedance shield 356. This metal block can also be constituted by a combination of metal members.

(Effect of double-sided discharge)
The effect of the present embodiment will be described with reference to FIGS.
FIGS. 21 and 22 are graphs showing examples of variations in the etching amount on the substrate when the substrate is etched by the etching apparatus of the reference example that does not use the above-described space constraining component and holder. FIG. 21 shows the measurement result on the front side of the substrate, and FIG. 22 shows the measurement result on the back side of the substrate. The etching amount indicates the thickness of the surface layer removed per unit time. The removal amount of the thin film previously formed on the substrate is measured. The reference line in the figure is targeted as the etching amount for obtaining the adhesion between the substrate and the film.

  Note that the horizontal axis of FIGS. 21 and 23 indicates the vertical position of the vertically arranged substrate 150 as shown in FIG. The vertical axis represents the etching amount. The graph uses the position on the substrate in the traveling direction of the substrate 150 as a parameter. The position in the advancing direction is a position in the left-right direction (advancing direction in the chamber) of the vertically placed substrate 150, and six positions are selected as measurement positions in the forward and reverse directions at intervals of 50 mm with reference to the center position of the substrate.

  As can be seen from FIG. 21 and FIG. 22, the variation in the etching amount on the front surface and the back surface is large. In particular, the variation in the etching amount on the back surface is large, and the minimum value and the maximum value of the etching amount are several tens of times.

  23 and 24 show the results of etching with the etching apparatus of this example. The display of the graph is the same as in the comparative example.

  Comparing the example of the present invention with the comparative example, it can be seen that although the average value of the etching amount is satisfactory, the variation in the etching amount is several times larger when the present invention is not applied. This is considered to be due to the difference in the space symmetry and plasma diffusion of the chambers on both sides of the substrate to be processed. Etching is performed for a certain period of time so as to remove a certain range of amounts. Therefore, the target is not achieved or varies, and in particular, the amount of local removal is a problem in quality. According to the present embodiment, a uniform surface treatment state is obtained between both surfaces of the substrate and within the same surface by adjusting the electrical constant between each surface of the substrate and each counter electrode substantially the same.

(Effect of single-sided discharge)
As described above, the effect of stopping the etching of the surface (closing the discharge space on one side) can be obtained by bringing the movable counter electrode closer to the substrate within a predetermined distance. Thereby, a single-sided etching process can be performed in a double-sided etching processing apparatus.

  FIG. 26 is a graph showing a discharge state with respect to changes in the process gas flow rate and the high-frequency output when etching on only one side is continuously performed. In the figure, the horizontal axis represents the supply high-frequency power (W), and the vertical axis represents the flow rate (cc / min) of the process gas. In the figure, ◯ indicates a state in which the discharge is stable, and x indicates a state in which the discharge is unstable. Judgment of stability and instability was judged from the state of reflected wave power.

  From the figure, it was found that the process gas flow rate range in which stable discharge can be obtained even by etching on only one side is wide. There is no dependency on the etching output in the flow region of the process gas, and discharge at a lower output than before is possible. Further, there can be mentioned advantages such as a process capable of stable continuous discharge only with the process gas and not subject to the restriction of the presence or absence of other additive gases. Therefore, a process with a large margin for changes in flow rate, power supply, etc. can be performed.

  The present invention is advantageously applied to a plasma processing apparatus such as a thin film forming apparatus for metal thin plates using a vacuum, such as a separator as a fuel cell component, and an etching apparatus.

FIG. 1 is a sectional view for explaining an example of an etching apparatus as a surface treatment apparatus of the present invention. FIG. 2 is a plan view for explaining an example of a substrate, a holder, and a tray. FIG. 3 is a cross-sectional view illustrating an example in which the counter electrode of the etching apparatus is movable. FIG. 4 is an explanatory diagram for explaining the operation of the etching apparatus. FIG. 5 is an explanatory diagram for explaining an external variable impedance (matching box). FIG. 6 is a flowchart for explaining the operation procedure of the etching apparatus. FIG. 7 is an explanatory diagram for explaining an example of an etching apparatus provided with an internal variable impedance. FIG. 8 is also an explanatory diagram illustrating an example of an etching apparatus provided with an internal variable impedance. FIG. 9 is an explanatory view illustrating an example of a thin film forming apparatus including the etching apparatus. FIG. 10 is a perspective view for explaining a specific example of the etching apparatus of the present invention. FIG. 11 is a right side view of the etching apparatus shown in FIG. FIG. 12 is a perspective view illustrating an example of a box reflector (counter electrode) used in the embodiment. FIG. 13 is a perspective view illustrating an example in which the bottom plate (counter electrode) of the box reflector is moved. FIG. 14 is a perspective view illustrating an example of an impedance shield (an example of three divisions). FIG. 15 is a perspective view for explaining another example (non-divided example) of the impedance shield. FIG. 16 is a perspective view for explaining an attached state of the impedance shield on one side. FIG. 17 is a perspective view for explaining the impedance shield on the other side. FIG. 18 is a perspective view for explaining the substrate and holder placed on the tray. FIG. 19 is a perspective view illustrating a configuration example of the metal block portion on one side. FIG. 20 is a perspective view illustrating a configuration example of the metal block portion on the other side. FIG. 21 is a graph showing the etching state of the substrate surface by the etching apparatus of the reference example. FIG. 22 is a graph showing an etching state of the back surface of the substrate by the etching apparatus of the reference example. FIG. 23 is a graph showing an etching state of the substrate surface by the etching apparatus of the example. FIG. 24 is a graph showing an etching state of the back surface of the substrate by the etching apparatus of the example. FIG. 25 is an explanatory diagram for explaining the measurement position on the substrate. FIG. 26 is a graph for explaining an example of a discharge state in which the process gas flow rate and high-frequency power of the etching apparatus of the example are parameters.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thin film forming apparatus, 10 tray carrying-in apparatus, 20 loading apparatus, 30 etching apparatus, 40 1st sputtering apparatus, 50 2nd sputtering apparatus, 60 unloading apparatus, 70 tray carrying out apparatus, 80 tray return apparatus, 100 tray, 120 holder, 121 power supply terminal, 131, 132 clamp, 150 substrate, 301, 351 base frame, 302, 352 box reflector, 303, 353 counter electrode, 304, 354 actuator, 305, 355 guide, 306, 307 impedance shield

Claims (32)

A surface treatment method for processing a member to be processed having a plurality of surfaces by plasma discharge treatment,
A process of disposing a member to be processed between a plurality of counter electrodes disposed in the chamber;
A process of measuring the electrical constant of the chamber by performing plasma discharge between the member to be processed and the plurality of counter electrodes;
An adjustment process for adjusting the relative positional relationship between the member to be processed and the plurality of counter electrodes facing the member based on the measurement result;
Surface treatment of the member to be treated with plasma between the member to be treated and the plurality of counter electrodes;
A surface treatment method comprising:   2. The surface treatment according to claim 1, wherein the adjustment process adjusts the relative positional relationship so that electric constants between the member to be processed and the plurality of counter electrodes opposed thereto are substantially equal. Method. A surface treatment method for processing a member to be processed having a plurality of surfaces by plasma discharge treatment,
A process of disposing a member to be processed between a plurality of counter electrodes disposed in the chamber;
A process of measuring the electrical constant of the chamber by performing plasma discharge between the member to be processed and the plurality of counter electrodes;
Adjusting the variable impedance disposed between the member to be processed and each of the plurality of counter electrodes based on the measurement result;
A process of simultaneously processing the plurality of surfaces to be processed by the plasma between the member to be processed and the plurality of counter electrodes;
A surface treatment method comprising:   4. The surface treatment method according to claim 3, wherein the adjustment process adjusts the variable impedance so that electric constants between the member to be processed and the plurality of counter electrodes facing the member to be processed are substantially equal. .   The surface treatment method according to claim 1, wherein the member to be treated is disposed in the chamber with a peripheral edge held by a holder.   The surface treatment method according to claim 1, wherein the member to be treated is connected to a high-frequency power source via a conductive holder at a peripheral edge thereof.   5. The surface treatment method according to claim 1, wherein there are a plurality of the members to be treated, and an edge of each member to be treated is held by one conductive holder and connected to a high-frequency power source through the holder. .   In the adjustment process, the electrical constants of the treated surfaces and the counter electrodes corresponding to the treated surfaces are measured in advance on a plurality of treated surfaces of the treated member, and the electrical constants of the treated surfaces are substantially equal. And determining the positional relationship between each surface to be processed and the plurality of counter electrodes corresponding to these surfaces, and determining the positional relationship between the plurality of counter electrodes corresponding to the target member introduced into the chamber. The surface treatment method according to claim 1, wherein the surface treatment method is set.   The surface treatment method according to claim 8, wherein the setting of the positional relationship between the plurality of counter electrodes sets the shape of the plasma generation space in the chamber corresponding to the member to be processed.   The surface treatment method according to claim 1, wherein the member to be treated is a flat plate having front and back surfaces.   The surface treatment method according to claim 1, wherein the flat plate is a fuel cell separator.   The surface treatment method according to claim 1, wherein the plasma discharge treatment is etching or film formation.   The said adjustment process changes the state of the surface treatment of each surface by adjusting the relative positional relationship of the to-be-processed surface of the said to-be-processed member, and the said counter electrode corresponding to this surface. 12. The surface treatment method according to any one of 12 above.   The adjustment process is to inactivate the surface treatment on the surface to be processed by setting a distance between one surface to be processed of the member to be processed and a counter electrode facing the surface to a predetermined value or less. The surface treatment method according to claim 1. A surface treatment apparatus for processing a member to be processed having a plurality of surfaces by plasma discharge treatment,
A plurality of counter electrodes arranged to face a plurality of surfaces to be processed of the member to be processed,
A chamber for maintaining the processing target member and the plurality of counter electrodes in an atmosphere of a process gas;
Adjusting means for adjusting the relative positional relationship between the member to be processed and the plurality of counter electrodes for each surface to be processed;
A high-frequency power source that supplies high-frequency power between the member to be processed and the plurality of counter electrodes to generate plasma between the plurality of surfaces to be processed and the plurality of counter electrodes;
A surface treatment apparatus comprising:   The surface treatment apparatus according to claim 15, wherein the adjustment unit sets the relative positional relationship so that an electric constant between the member to be treated and the counter electrode is substantially equal for each surface to be treated. A surface treatment apparatus for processing a member to be processed having a plurality of surfaces by plasma discharge treatment,
A plurality of counter electrodes respectively disposed to face a plurality of surfaces to be processed of the member to be processed;
A chamber for maintaining the processing target member and the plurality of counter electrodes in an atmosphere of a process gas;
A variable impedance electrically connected between the member to be processed and each of the plurality of counter electrodes;
Adjusting means for adjusting the electric constant between the member to be processed and the counter electrode for each surface to be processed;
A high-frequency power source that supplies high-frequency power between the member to be processed and the plurality of counter electrodes to generate plasma between the plurality of surfaces to be processed and the plurality of counter electrodes;
A surface treatment apparatus comprising:   The adjusting means adjusts at least one of a relative positional relationship between the surface to be processed of the member to be processed and the counter electrode and the variable impedance, and sets the electrical constant for each surface to be processed. Item 18. The surface treatment apparatus according to Item 17.   The adjusting means measures in advance the electrical constants of the treated surfaces and the counter electrodes corresponding to the treated surfaces of the treated members, so that the electrical constants of the treated surfaces are substantially equal. The positional relationship between each surface to be processed and the plurality of counter electrodes corresponding to these surfaces is determined, and the positional relationship between the plurality of counter electrodes corresponding to the target member introduced into the chamber The surface treatment apparatus according to claim 15 or 17, wherein:   The surface treatment apparatus according to claim 19, wherein the setting of the positional relationship between the plurality of counter electrodes is a shape setting of a plasma generation space in the chamber corresponding to the member to be processed.   The adjusting means is configured to change a surface treatment state of each surface by adjusting a relative positional relationship between a surface to be processed of the member to be processed and the counter electrode corresponding to the surface. The surface treatment apparatus according to 17.   The adjusting means inactivates the surface treatment on the surface to be processed by setting a distance between one surface to be processed and the counter electrode facing the surface to be a predetermined value or less. The surface treatment apparatus according to claim 15 or 17, wherein   The surface treatment apparatus according to any one of claims 15 to 22, wherein an edge of the member to be treated is held in a holder while being held by a holder.   The surface treatment apparatus according to any one of claims 15 to 23, wherein an edge of the member to be treated is held by a conductive holder and is electrically connected to a high frequency power source through the holder.   The surface treatment apparatus according to claim 15, wherein the member to be treated is a flat plate having front and back surfaces.   The surface treatment apparatus according to any one of claims 15 to 25, wherein the flat plate is a fuel cell separator.   The surface treatment apparatus according to any one of claims 15 to 26, wherein the plasma discharge treatment is etching or film formation. First and second electrodes that are spaced apart such that the concave openings face each other;
A substrate disposed between the first and second electrodes so that a surface to be processed faces the opening and the region of the surface to be processed is within the region of the opening;
A chamber for maintaining the first and second electrodes and the substrate in a reduced pressure atmosphere;
Gas supply means for supplying a process gas into the chamber;
A high frequency power source for supplying high frequency power between the substrate and the first and second electrodes to turn the process gas into plasma;
A surface treatment apparatus comprising:   29. The surface treatment apparatus according to claim 28, wherein the concave openings of the first and second electrodes are formed in a similar shape.   30. The surface treatment apparatus according to claim 28, wherein each of the first and second electrodes includes a movable electrode that is disposed at a bottom of the concave opening and moves forward and backward in the substrate direction.   31. The surface treatment apparatus according to claim 28, wherein electrical constants between the first and second electrodes and the substrate are set to be substantially equal. 32. The surface treatment apparatus according to claim 28, wherein the first and second electrodes have a box shape.

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